U.S. patent number 8,828,044 [Application Number 13/370,912] was granted by the patent office on 2014-09-09 for obstruction capture and removal device.
This patent grant is currently assigned to Cook Medical Technologies LLC. The grantee listed for this patent is Steen Aggerholm, Bente Weber Christensen, Per Hendriksen, Thomas Lysgaard, Arne Molgaard Nielsen, Frank Svendsen. Invention is credited to Steen Aggerholm, Bente Weber Christensen, Per Hendriksen, Thomas Lysgaard, Arne Molgaard Nielsen, Frank Svendsen.
United States Patent |
8,828,044 |
Aggerholm , et al. |
September 9, 2014 |
Obstruction capture and removal device
Abstract
A thrombus retrieval device (10) includes a flexible catheter
(12), a retrieval wire (26) fixed to the distal end (14) of the
catheter (12) and which extends out of the catheter (12) at first
and second apertures in the wall of the catheter (12). A trap
element (28) typically made of a porous fabric material, is
attached to the catheter (12) from the distal end (14) across the
location of the apertures. The trigger wire (26) can be pulled in a
proximal direction, which causes the catheter (12) to twist so as
to form a loop. The trap element (28), attached to the catheter at
location in which it loops, forms a net for trapping thrombi or
other obstructions within a patient's lumen.
Inventors: |
Aggerholm; Steen (St. Heddinge,
DK), Christensen; Bente Weber (Ringsted,
DK), Hendriksen; Per (Herlufmagle, DK),
Lysgaard; Thomas (Solroed Strand, DK), Nielsen; Arne
Molgaard (Copenhagen, DK), Svendsen; Frank
(Ringsted, DK) |
Applicant: |
Name |
City |
State |
Country |
Type |
Aggerholm; Steen
Christensen; Bente Weber
Hendriksen; Per
Lysgaard; Thomas
Nielsen; Arne Molgaard
Svendsen; Frank |
St. Heddinge
Ringsted
Herlufmagle
Solroed Strand
Copenhagen
Ringsted |
N/A
N/A
N/A
N/A
N/A
N/A |
DK
DK
DK
DK
DK
DK |
|
|
Assignee: |
Cook Medical Technologies LLC
(Bloomington, IN)
|
Family
ID: |
43859306 |
Appl.
No.: |
13/370,912 |
Filed: |
February 10, 2012 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20120209312 A1 |
Aug 16, 2012 |
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Foreign Application Priority Data
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Feb 11, 2011 [GB] |
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1102458.5 |
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Current U.S.
Class: |
606/200;
606/127 |
Current CPC
Class: |
A61B
17/221 (20130101); A61B 2017/2212 (20130101); A61B
2017/00287 (20130101) |
Current International
Class: |
A61B
17/22 (20060101) |
Field of
Search: |
;606/113,114,127,200,110-112,128 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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195566 |
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Feb 1958 |
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AT |
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688834 |
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Mar 1940 |
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DE |
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2436352 |
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Feb 1976 |
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DE |
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3913936 |
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Oct 1990 |
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DE |
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09019438 |
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Jan 1997 |
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JP |
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93/02732 |
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Feb 1993 |
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WO |
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Other References
12154535.4-1659/2486875 European Search Report Sep. 25, 2013. cited
by applicant.
|
Primary Examiner: Holwerda; Kathleen
Attorney, Agent or Firm: Godlewski; Richard J.
Claims
What is claimed is:
1. An object capture device for capturing an object from a body
vessel, including: a flexible catheter provided with a distal end
and a proximal end; at least one opening in a side of the flexible
catheter, the at least one opening providing spaced catheter entry
and exit points for a trigger wire; a trigger wire located within
the flexible catheter and attached to or proximate the distal end
of the catheter, the trigger wire passing out of the catheter
through the exit point and then back into the catheter through the
entry point; a flexible trap element attached to the catheter
across the at least one opening, the trap element being detached
from the trigger wire; and wherein retraction of the trigger wire
causes the catheter to twist into a loop about the at least one
opening, said twisting action causing the trap element to form a
capture chamber.
2. A device according to claim 1, wherein the at least one opening
comprises a slot with two ends, the slot extending longitudinally
along a portion of the catheter, the ends of the slot providing the
entry and exit points for the trigger wire.
3. A device according to claim 1, wherein the trap element is sized
and arranged so as to locate relatively closely against the
catheter when the catheter is in a straight configuration.
4. A device according to claim 1, wherein the trap element is
shaped so as to create a generally conical capture chamber.
5. A device according to claim 1, wherein the trap element is made
of a porous material.
6. A device according to claim 5, wherein the trap element has
holes or pores sufficiently small to trap obstructing material and
large enough to allow the passage of blood.
7. A device according to claim 1, wherein the trap element is made
of a substantially impermeable material provided with one or more
openings therein.
8. A device according to claim 1, wherein the trap element is
attached to the catheter across the location of the at least one
opening.
9. A device according to claim 1, wherein the opening comprises at
least first and second longitudinally spaced holes in the wall
thereof.
10. A device according to claim 1, wherein a distal end of the
trigger wire is fixed to or proximate the distal end of the
catheter.
11. A device according to claim 1, wherein the catheter is provided
with more than two holes in a wall thereof.
12. A device according to claim 1, wherein the entry and exit
points provided by the opening or openings are spaced so as to form
a twisted loop which has a diameter substantially equivalent to the
diameter of the lumen into which the device is to be used.
13. A device according to claim 1, wherein the catheter provides a
lumen for a guide wire.
14. A device according to claim 1, wherein the trap element is made
of nylon mesh.
15. An object capture device for capturing an object from a body
vessel, including: a flexible catheter provided with a distal end
and a proximal end, the proximal end remaining outside of the
patient during a procedure; at least one opening in a side of the
flexible catheter, the at least one opening providing spaced
catheter entry and exit points for a trigger wire; a trigger wire
located within the flexible catheter and attached to or proximate
the distal end of the catheter, the trigger wire passing out of the
catheter through the exit point and then back into the catheter
through the entry point; a flexible trap element attached to the
catheter across the at least one opening, the trap element
comprising at least two edges and fixed to an outer surface of the
catheter along two of the edges; wherein retraction of the trigger
wire causes the catheter to twist into a loop about the at least
one opening, said twisting action causing the trap element to form
a capture chamber.
16. A device according to claim 15, wherein the trap element is
detached from the trigger wire.
17. An object capture device for capturing an object from a body
vessel, including: a flexible catheter provided with a distal end
and a proximal end, the proximal end remaining outside of the
patient during a procedure; an opening in a side of the flexible
catheter extending longitudinally along the catheter in the form of
a slot, with the ends of the slot providing an entry point and an
exit point for the trigger wire; a trigger wire located within the
flexible catheter and attached to or proximate the distal end of
the catheter, the trigger wire passing out of the catheter through
the exit point and then back into the catheter through the entry
point; a flexible trap element attached to the catheter across the
opening, the trap element comprising at least two edges and fixed
to an outer surface of the catheter along two of the edges; wherein
retraction of the trigger wire causes the catheter to twist into a
loop about the opening, said twisting action causing the trap
element to form a capture chamber.
18. A device according to claim 17, wherein the trap element is
detached from the trigger wire.
Description
TECHNICAL FIELD
The present invention relates to an obstruction capture and removal
device, in the preferred embodiment for the removal of thrombi or
debris from blood vessels.
BACKGROUND OF THE INVENTION
Mechanical thrombectomy is a procedure which has been in widespread
use for many years. Typical thrombectomy devices are balloons which
are inflated in a vessel and then withdrawn to pull thrombi into a
sheath and then withdrawn from the patient. Other devices are
simple open ended catheters into which a thrombus is aspirated and
removed from the patient. Another thrombectomy device employs a
basket that is opened within the thrombus so that the thrombus
becomes captured in the basket. The basket can then be retrieved
taking the thrombus with it. Still other devices use a small
corkscrew shaped device which is collapsed inside a catheter. The
catheter is passed through the thrombus, the corkscrew is pushed
out of the catheter allowing the device to expand, thereby
capturing the thrombus for removal. Some corkscrew devices are
simply "screwed" into the thrombus, then retracted into a catheter
for removal before the corkscrew is retracted.
Known devices are disclosed in U.S. Pat. No. 7,052,500,
US-2006/0,224,179 and US-2008/0,275,464.
Aspirating the thrombus into a catheter can cause breaking up of
the thrombus during the procedure. Furthermore, where a thrombus is
located in a very narrow vessel, the size of the catheter is too
small and unable to house the thrombus within its lumen.
SUMMARY OF THE INVENTION
The present invention seeks to provide an improved obstruction
removal device.
According to an aspect of the present invention there is provided
an object capture device for capturing an object from a body
vessel, including a flexible catheter provided with a distal end
and a proximal end; at least one opening in a side of the flexible
catheter, the at least one opening providing spaced catheter entry
and exit points; a trigger wire located within the flexible
catheter and attached to or proximate the distal end of the
catheter; a flexible trap element attached to the catheter across
the at least one opening; wherein retraction of the trigger wire
causes the catheter element to twist into a loop about the at least
one opening, said twisting action causing the trap to form a
capture chamber.
In practice, the trap element is sized and arranged so as to locate
relatively closely against the catheter so as to enable the device
to have a small diameter, or footprint, when the catheter is in an
extended, that is straight or not twisted configuration. This can
be by means of a combination of the size of the trap element and
the spacing of points at which it is fitted to the catheter.
The preferred embodiments of device taught herein provide a number
of advantages over known art. For example, the devices taught
herein are able to capture the entirety of a thrombus or debris
without breaking this up during the capture or removal operation,
as occurs with some prior art systems. The devices are also able to
provide a complete trap able to close off the entire diameter of
the vessel and thus to capture all of the thrombus or other debris
material, including small fragments. The preferred devices are also
able to be constructed in an introducer assembly which is flexible
and has a small footprint, able to be passed through small diameter
vessels and tortuous vasculature.
It is preferred that the trap element is shaped so as to create a
generally conical capture chamber, thereby to have a wide opening
and a narrow base.
The trap element may be made of a substantially impermeable
material, possibly with one or more small openings therein, but it
is preferably made from a porous material having pores sufficiently
small to trap obstructing material, such as a thrombus, but large
enough to allow the passage of blood or other fluid. In this
regard, the trap may be made of a netting or mesh type material. An
example is fine nylon mesh, which is very flexible and can retain a
stable mesh size during use.
The trap element is preferably attached to the catheter across the
location of the hole or holes. Thereby, the twisted loop will form
the entry point into the trap and will also provide a support at
the opening.
In the preferred embodiment, the catheter is provided with at least
first and second longitudinally spaced holes in its side wall. The
trigger wire, which normally passes within the lumen of the
catheter, passes out through one hole and then back into the
catheter lumen through the second hole. The distal end of the
trigger wire is fixed to or proximate the distal end of the
catheter. Thus, when the trigger wire is pulled back, this will
cause the catheter to twist between the first and second holes and
thus to cause the trap element to conform to the chamber
configuration.
There may be provided more than two holes in the catheter wall.
Having a greater number of holes enables a choice of entry and exit
points for the trigger wire, thus the size of twisted loop which is
formed on puling back of the wire. Similarly, by providing multiple
pairs of entry and exit points, a plurality of twisted loops can be
created in the catheter, preferably for a plurality of trap
chambers (formed either from a single trap element or from a
plurality of trap elements).
In an embodiment, there may be provided in the catheter a single
opening. In this embodiment, the opening would extend
longitudinally along the catheter, in the form of a slot, with the
ends of the opening providing the entry and exit points for the
trigger wire. Upon pulling of the trigger wire, this will be pulled
out of the catheter through the slot and thus be able to twist the
catheter into the loop.
Advantageously, the entry and exit points provided by the opening
or openings are spaced so as to form a twisted loop which has a
diameter substantially equivalent to the diameter of the lumen into
which the device is to be used.
The catheter may provide, through the lumen described above or
through a different lumen, a lumen for a guide wire. In the case of
a single lumen, the trigger wire may be positioned to a side of the
wall of the catheter.
Preferably, there is provided an introducer sheath through which
the device can be fed to the target site.
According to another aspect of the present invention, there is
provided a method of capturing an object from a body vessel by
means of a device including a flexible catheter provided with a
distal end and a proximal end; at least one opening in a side of
the flexible catheter, the at least one opening providing spaced
catheter entry and exit points; a trigger wire located within the
flexible catheter and attached to or proximate the distal end of
the catheter; a flexible trap element attached to the catheter
across the at least one opening; the method including the steps of:
locating the device is a patient's vessel; retracting the trigger
wire in a proximal direction thereby to cause the catheter element
to twist into a loop about the at least one opening and the trap to
form a capture chamber; and trapping an object within the capture
chamber.
Preferably the method includes the step of removing the object from
the patient while the object is retained in the trap.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention are described below, by way of
example only, with reference to the accompanying drawings, in
which:
FIG. 1 shows schematically an embodiment of object removal device
in an extended, delivery, configuration;
FIG. 2 shows the device of FIG. 1 in a position prior to
deployment;
FIG. 3 shows the device of FIG. 1 at the start of the process of
pulling the trigger wire thereof;
FIG. 4 shows the device of FIG. 1 with the trigger wire pulled back
fully and the catheter twisted into a loop;
FIG. 5 shows detail of the distal end of another embodiment of the
device of FIG. 1; and
FIG. 6 shows detail of the distal end of yet another embodiment of
the device of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It is to be understood that the Figures are schematic and do not
show the various components to their actual scale. In many
instances, the Figures show scaled up components to assist the
reader in the understanding of the features disclosed therein.
In this description, the term distal is used to refer to an end of
a component which in use is furthest from the surgeon during the
medical procedure, including within a patient. The term proximal is
used to refer to an end of a component closest to the surgeon and
which, in practice, may be in or adjacent an external manipulation
part of the deployment or treatment apparatus.
Referring now to FIG. 1, there is shown schematically an embodiment
of object removal device 10 which can be used for retrieving
obstructions, such as thrombi, from patient vessels. The device 10
shown in FIG. 1 would typically be introduced into the vasculature
of a patient via a carrier sheath, of a type well known in the
art.
The device 10 includes a flexible catheter 12 having a distal end
14. The catheter 12 also has a proximal end 36, shown schematically
in FIG. 2, which extends to an external manipulation end or handle
unit 38 of the device 10. The proximal end 36 of the catheter 12
would remain outside the patient during the medical procedure,
which allows for control and operation by a clinician.
The catheter element 12 is preferably made of a flexible and
relatively springy material, such as a plastics material or even a
metal. It is envisaged also that the catheter 12 could be made of a
shape memory material to provide this with the desired
elasticity.
The catheter 12 has a lumen 20 extending through substantially its
entire length (it could, however, be closed off at its distal end
14 in some embodiments). Proximate its distal end 14, the catheter
12 has distal and proximal apertures or holes 22, 24 in its
wall.
A trigger wire 26, is in this embodiment is fixed to the distal end
14 of the catheter 12 and passes from within the lumen 20 of the
catheter 12 out of the aperture 22 then back into the lumen 20
through the proximal aperture 24. The trigger wire 26 is fixed at
or close to the distal end 14 of the catheter 12 by any suitable
mechanism such as bonding, tying (knotting), welding and so on.
With reference to FIG. 2, the trigger wire 26 extends through the
lumen 20 of the catheter 12 to the proximal end 36 of the device
10, that is in practice to the external manipulation unit 38. The
trigger wire 26 is thus held at its distal end but loose at its
proximal end.
The trigger wire 26 can be made of any of the materials commonly
used in introducer assemblies, including steel, Nitinol, for
example.
Attached to the catheter 12 is a flexible trap element 28, which is
fixed to the outer surface of the catheter 12 along two of its
edges 30. As can be seen in the drawings, the trap element 28
extends from close to the distal end 14 of the catheter, indicated
as location 32, to a location 34. Typically, as will become
apparent from the description which follows, the edges 30 of the
trap element 28 are fixed to the catheter 12 for at least a
distance (L), which is substantially equal, in the preferred
embodiment, to the circumference of the trap once deployed and
preferably also substantially equal the circumference of the vessel
in which the device 10 is used.
The trap element 28 is advantageously made from a porous fabric
material such as a mesh or netting, although it could equally be
made of a non-porous material with at least one aperture therein to
allow the flow of fluid therethrough. An example of material is
fine nylon mesh, which is very flexible and can retain a stable
mesh size during use.
It is preferred that the trap 28 is of a type which can trap all
required debris and yet which allows the flow liquid therethrough
including blood plasma. In practice, the material forming the trap
28 will have pore sizes sufficient to trap thrombus particles.
Referring now to FIG. 2, there is shown the proximal end of the
assembly 10, which includes the proximal end 36 of the catheter 12,
which is attached to an external manipulation unit 38 shown only
schematically in FIG. 2 but which would have a form and components
readily appreciated by the person skilled in the art.
In FIG. 2 the trigger wire 26 is shown to curve out of the catheter
12 but this is only for the purposes of explanation. In practice,
the trigger wire 26 rests close to, and in some embodiments within,
the catheter 12 when the assembly is in its straight configuration
as shown in FIGS. 1 and 2.
The trigger wire 26 is able to be pulled in a proximal direction at
the external manipulation end 38 of the device 10. This action
causes the trigger wire 26 to pull the distal end 14 of the
catheter 12 proximally, by virtue of the trigger wire 26 being
fixed to the distal end 14. It is to be appreciated that this
pulling force will act against the stiffness of the catheter 12,
particularly at the location of the holes 22, 24 and thus of the
trap element 28.
FIG. 3 shows the trigger wire 26 having been pulled sufficiently as
to cause the distal end of the catheter 12 to begin to flex into a
curve, in practice causing the holes 22, 24 to come closer together
as the trigger wire 26 is effectively shortened.
FIG. 4 shows the trigger wire 26 having been pulled to the maximum
amount, such that the catheter at the holes 22, 24 come into
abutment with one another. At this point, the catheter 12 has bent
into a loop 40 and the trap element 28 has taken the form of a
closed conical net. In particular, the trap element 28 opens with
the loop 40, by virtue of being attached to the catheter 12, and is
closed at its distal end 32 by virtue of its edges or sides 30
being likewise fixed to the catheter wall.
FIG. 4 is to be taken as a schematic illustration of the device in
that the loop 40 is shown to be laterally offset from the remainder
of the catheter 12. In practice this offset will not exist or would
be minimised, to ensure that the loop 40 in practice can extend
across the entirety of the width of a vessel.
There can be seen in FIG. 4 a thrombus 42 just proximally of the
trap 28 and which in practice will be caught within the trap 28 as
fluid flows through the trap.
Once the obstruction has been caught in the trap 28, the pulling
force applied to the trigger wire 26 can be released. So doing
causes, in light of the resiliency of the device, the catheter
element 12 to regain its straightened shape as shown in FIGS. 1 and
2 or a configuration approaching this. The thrombus 42 or other
obstruction captured within the trap 28 would be retained within
the material of the trap 28. This allows for easy removal of the
device 10 from within a patient's vasculature (typically through a
carrier sheath (not shown)), with the obstruction held
therewithin.
The assembly shown in FIGS. 1 to 4 could have a catheter 12 which
has consistent characteristics such as flexibility throughout its
length. The arrangement of the trigger wire 26 and the holes 22, 24
in this embodiment would sufficient cause the catheter to flex into
the loop 40 shown in FIG. 4. In other embodiments, the catheter 12
may be more flexible around its distal end 14, typically from
around the position of the proximal hole 24, compared to the
remainder of its extend. This may be achieved by making the
catheter 12 of different materials along its length, by thinning
the walls of the catheter 12 at this location or in any other
suitable manner.
FIG. 5 shows a slightly different embodiment of device 100, having
the same characteristics as the embodiment taught above, differing
in having a plurality of apertures 128, 130, 134, 136 therein.
These apertures enable the trigger wire 26 to be fed into and out
of the lumen 132 in a plurality of different configurations,
thereby to be able to create different sized loops of twisted
catheter 112 when the trigger wire 26 is pulled back. In a
preferred embodiment, there would be provided a plurality of
trigger wires, each coupled through a respective aperture and
marked for the clinician's reference. Pulling on one of the trigger
wires will cause the trap to form, of a size related to the
position of that trigger wire. Thus, the characteristics of the
trap element can be varied.
It is also possible by this arrangement to form a plurality of
different loops 40 within the device 100, in one embodiment by
providing a plurality of different sections of trap material 116.
This would be achieved, for instance by having the trigger wire 26
extend out in two different locations of the catheter element 112.
This embodiment has the advantage of being able to adjust the
characteristics of the trap in a single device to suit different
lumen sizes.
The number of apertures that the catheter 112 could be chosen as
desired and preferred, and so can the relative spacings from one
aperture to another.
FIG. 6 shows yet another embodiment of retrieval device 200 which
includes a flexible catheter 212 having a lumen 232 therein and a
distal end 214. A trap element 216 is attached to the catheter 212.
The catheter 200 has characteristics equivalent to those of the
embodiments described above. In place of a plurality of openings in
the wall of the catheter 12, the embodiment FIG. 6 has a single
opening which is in the form of a slot 210. The slot 210 may have
enlarged apertures at its ends, as shown in the Figure. The slot
210 allows the trigger wire (not shown in FIG. 6) to extend out of
the slot 210 when this is pulled, in order to cause the catheter
212 to twist and loop in the manner shown, for example, in FIGS. 3
and 4.
It would also be possible to locate the trigger wire on the outside
of the catheter 212, for instance by fixing this at points along
the catheter 12, for example through fixing hooks which allow the
catheter to twist and loop when the trigger wire is pulled. In such
an event, it would not be necessary to have a catheter with a lumen
but have simply a flexible rod or wire.
In the embodiments which use a catheter, the lumen within the
catheter can be used also for a guide wire of known form. In this
regard, the catheter may have a single lumen 20, 132, 232 which
would accommodate both the trigger wire and a guide wire or could
be a multi-lumen catheter. The catheter can also be used for other
purposes, such as for flushing and the like.
It is envisaged that the device 10, 100, 200 will have a very small
footprint, that is have a very small outer diameter, particularly
in some embodiments, in order for this to be useable also very
small lumens, such as the cerebral arteries. The device 10, could
for instance, have a diameter of the order of 6 French or less. Of
course, the device could also usefully be designed for treatment
within larger vessels such as the main arteries.
It is not excluded that the device 10, 100, 200 could form a loop
40 which is smaller than the diameter of the lumen within which the
device is deployed, in which case the clinician would steer the
loop 40 within a patient's vessel in order to catch a thrombus like
the obstruction to be retrieved.
The disclosure of the abstract accompanying this application is
incorporated herein by reference.
* * * * *